LSNRCTL> status
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=lixora)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 10.2.0.1.0 - Production
Start Date                11-AUG-2014 00:42:37
Uptime                    0 days 0 hr. 24 min. 32 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /u02/app/oracle/product/10.2.0/db_1/network/admin/listener.ora
Listener Log File         /u02/app/oracle/product/10.2.0/db_1/network/log/listener.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=lixora)(PORT=1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC0)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "ora10g" has 1 instance(s).
  Instance "ora10g", status READY, has 1 handler(s) for this service...
Service "ora10gXDB" has 1 instance(s).
  Instance "ora10g", status READY, has 1 handler(s) for this service...
Service "ora10g_XPT" has 1 instance(s).
  Instance "ora10g", status READY, has 1 handler(s) for this service...
The command completed successfully
LSNRCTL>

关于‘Instance "ora10g", status READY, has 1 handler(s) for this service...’
中status 状态解释：
这个status 指的的是instance 的状态

Instance Specifies the name of the instance associated with the service along
with its status and number of service handlers associated with the
service
Status can be one of the following:
■ A READY  status means that the instance can accept connections.
-----实例是动态由pmon注册，所以显示的status 当然是‘ready’

■ A BLOCKED status means that the instance cannot accept connections.
-----实例无法接受连接，一般是实例处于nomount 状态下，pmon 无法将注册到监听，因为这时数据库还没有打开pmon无法确定db能否对外服务

■ A READY/SECONDARY  status means that this is a secondary instance in an Oracle9 i  Real Application Clusters
primary/secondary configuration and is ready to accept connections.

■ An UNKNOWN status means that the instance is registered statically in the  listener.ora file rather than dynamically
with service registra tion. Therefore, the status is non known.
------这个‘unknown’ 表征实例是静态注册到监听